How to fix 550 5.7.708 Service unavailable

Question

How to fix this. I can't see how to contact microsoft support. Also, my subscription to MS365 is beyond free period... so why is this happening and how to make it stop. very unprofessional to have this happen on a new account for my business. Only seems to happen now that my free trial has ended and only on larger companies.....

550 5.7.708

The complete NDR error message is as follows:

550 5.7.708 Service unavailable. Access denied, traffic not accepted from this IP.

This NDR is generated if you send an email message from an IP address that has a low reputation. The issue is more likely to affect new customers, such as those who have a Microsoft 365 trial subscription.

How do I fix this?

If you're an email admin, and you receive this error during a trial subscription, contact Microsoft Support to request an IP address exception until you assign Exchange Online licenses.

Answer 1

Hi @David Crowder ,

Welcome to our forum!

Looks like your case is more related to your paid Microsoft 365 product, please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. And i notice that you want the help of Microsoft support, please try to contact M365 support in the admin portal: 

Hope to help you!

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.